nfs: initialize timeout variable in nfs4_proc_setclientid_confirm

gcc (4.3.0) rightfully warns about this:
/usr0/export/dev/bhalevy/git/linux-pnfs-bh-nfs41/fs/nfs/nfs4proc.c: In function nfs4_proc_setclientid_confirm:
/usr0/export/dev/bhalevy/git/linux-pnfs-bh-nfs41/fs/nfs/nfs4proc.c:2936: warning: timeout may be used uninitialized in this function

nfs4_delay that's passed a pointer to 'timeout' is looking at its value
and sets it up to some value in the range: NFS4_POLL_RETRY_MIN..NFS4_POLL_RETRY_MAX
	if (*timeout <= 0)
		*timeout = NFS4_POLL_RETRY_MIN;
	if (*timeout > NFS4_POLL_RETRY_MAX)
		*timeout = NFS4_POLL_RETRY_MAX;

Therefore it will end up set to some sane, though rather indeterministic, value.

Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>